To assess strength it needs to be:
Objective– is measurable and easily quantified.Â
Reproducible– be able to obtain the same value upon repeated trials.
Valid– measures what it is suppose to measure, (i.e. bench press for upper body pushing strength).
Safe– can obtain a maximum effort without an undue risk for injury.
Calibration, Calibration, Calibration! The testing equipment or weights must be calibrated to know that the measured values are accurate.
To evaluate strength or power you would need to compare to standards for your sex, age and size. Males and females have varying ranges of strength and power when assessing performance standards. Strength and power measurements increase, often into the 30’s, and then show a gradual loss each decade thereafter for both males and females
Body size affects evaluation of strength and power.  Absolute strength (pounds of weight lifted) favors larger individuals, and relative strength (weight lifted per pound) favors smaller individuals.  Strength/power to weight ratios when performing maximal efforts approach a 2/3 exponential ratio to body mass.  If you are twice as big you’re not twice as strong but approximately 2/3 of twice as strong, (allometric scaling).
Figure 1: Predicted strength to weight ratios (mass to the power of 2/3), compared to actual strength to weight ratios for current world record Olympic weightlifters by weight class. (International Weightlifting Federation Web Page).  In the figure above the 105 kg weightlifting world record holder would grade a “C+†at 76.8% of body weight lifted compared to the 56 kg world record holder.  This is in fact what happens using a push-up for testing upper body strength.  It provides an uneven playing field for the testing of larger subjects.
Have a set protocol including explanation, warm up, and order of lifts. To minimize the risk of injury short aerobic exercise, stretches, and warm up sets before maximal efforts are obtained.
Obtain maximum effort without trial and error: Using free-weight exercises often involves trial and error to find maximum muscular efforts. When the actual max is finally achieved, the subject may have been fatigued through numerous attempts to find the maximum weight lifted. Using isokinetic assessment technology will avoid this issue, while at the same time assessing maximal strength and power throughout a full range of motion.
Minimize the effect of skill as a factor in obtaining a maximal performance: Pre and post testing can be affected because to the subjects lack of skill while lifting. Having a fixed range of motion lever arm that can be accommodated different subjects while eliminating the need for the fine motor control needed to balance the weight during maximal efforts.
Test more functional, multi-muscle groups lifts. Performing such lifts as Bench Press, Leg Press, Deadlift, Pulldowns, Shoulder Press involve multiple muscle groups allowing the ability to examine the kinetic chain of how they work together in gross motor movements
Obtain strength and power standards from an extensive and diverse population. Maximal efforts were obtained from 25,000 subjects with equal representation up into the 80’s age group.
Tests and standards are based on a 5 repetition maximum. Subjects can often show improvement by minimizing the loss of strength as a result of muscle fatigue over 5 repetitions. An estimated max is then computed based on the 5 repetition average, and used to grade the subject on a 0.00 to a 4.00 GPA scale.
Grading scheme: Grading must mean something. A zero to 4.00 Grade Point Average (GPA) would be easy for most everyone to understand. A 2.00 GPA is average. A 1.00 GPA represents one standard deviation below the group mean in a performance standard. A 4.00 GPA mean the subject exceeds the group mean by 2 two standard deviations which infers a 98 percentile. Most subjects will congregate around the average range where the majority of the population lies.
There is currently only one place in the United States that can perform strength and power evaluations incorporating these many crucial factors, make it fair, and grade the subject appropriately.
Exercise Science Center
1101 Regents Blvd
Fircrest WA 98466.
(253) 564-6050